Giant-Size Super-Heroes #1 should really be included in Vol. 14.

Granted, technically it could be looked at as a pre-cursor to the Giant Size "Team-Up" issues that follow starting with Giant-Size Spider-Man #1.  But this is not a team-up issue.  This is Spider-Man battling Man-Wolf and Morbius, and has a better home in the Amazing Spider-Man line where both of these characters were introduced.  These two were strictly Spidey foes at this point, and this book cannot be considered a "Team-Up" unless every issue of Amazing Spider-Man is also considered a team-up, such as Amazing Spider-man #2 should be considered a Spider-Man/Vulture team-up or Amazing Spider-Man #3 should be considered a Spider-Man/Doc Ock team-up.

It would really help the page count of this volume.  25 pages of story plus cover + 8 pinups. 

Also think the following from Marvel Treasury Edition #1 should be included
The front and back cover which includes great John Romita art.  The 2-page Daily Bugle "extra",  the table of contents for the issue which contains a nice headshot gallery and Stan's Spider-Man editorial from that issue.  All of these can be seen here:
http://www.giantsizemarve...sury-edition-1-a-su.html
There is also a pin-up in this issue not shown, which has Spider-Man bench pressing other heroes from the Marvel Universe which should also be included.

That's another 8 pages from Marvel Treasury.  So add another with Giant-Size and you got yourself a  nice 268 page Masterworks with a few extra pages for bios or other extra or what not.